1. Field of the Invention
The present invention relates to an antenna apparatus configured using a board.
2. Description of Related Art
A patch antenna is frequently used as an in-vehicle antenna for communicating with GPS (Global Positioning System), ETC (Electronic Toll Collection) system and the like, as is described in JP-2001-267834A for example.
Since the in-vehicle antenna is used in a noisy environment, antenna directivity is changed in accordance with an environmental change so that the in-vehicle antenna can perform communication in a noise reduced state. From a viewpoint of suppressing an increase in antenna apparatus size, it may be preferable that an orientation of an antenna apparatus be not changed by mechanical control but a characteristic of the antenna apparatus such as directivity, radiation pattern and the like be changed by electric control.
For a single antenna such as a patch antenna and the like, however, it has been difficult to largely change the directivity or the radiation pattern by electrical control only.